Furnace.



R. ZHESING.

FURNACE.-

APPLICATION FILED MAY 4. I916.

Patented Aug. 14, 1917.

//\/V f/\/ TOE RICHAKD ZIESINC:

flrrocwma- PATNT @FFIOE.

RICHARD ZIESING, or CLEVELAND, onro,

.ASSIGNOR TO THE GRASSELLI CHEMICAL SOIMPANY, OF CLEVELAND, OHIO, ACQRPORATION F OHIO.

FURNACE.

I Specification 01' Letters Patent.

Application filed May 4, 1916. Serial N 0. 95,314.

To allwiwm it may concern:

. of the means Be it known that I, RICHARD ZIESING, a citizen of theUnited States, and a resident of Cleveland, county of Cuyahoga, andState of Ohio, have invented a new and useful Improvement in Furnaces,of which the following is a specification, the principle of theinvention being herein explained and the best mode in which I. havecontemplated applying that principle, so as to distinguish it fromotherinventions.

The present invention relates to a method of, and apparatus for,purifying metals of othe and heavier metals mixed therewith andrelatesmore particularly to a method. of separating pure zinc from leadand iron contained therein. In the purification f zinc, it is necessaryto remove from the sol d metal, iron and lead, and the process must becarried out in the absence of air, the zinc being volatilized and drivenofi from the furnace chamber into a compensation tower.

o the accomplishment of theforegoing and related ends, said invention,then, consists hereinafter fully described and particularly pointed outin the claims.

The annexed drawing and the following description sets forth in detailone approved method of carrying out the invention, such disclosed mode,however, one of the various ways in which the prin ciple of theinvention maybe used.

In said annexed drawin Figure l, is a longitudinal vertical sectionthrough my improved furnace, and Fig. 2 is a transverse vertical sectionon the line 2-2, Fig. 1.

' chamber 2, is inclosed, except In Fig. 1, there is shown essentialparts of the furnace, and it will be seen that I have provided twochambers, -1 and 2, of whic the chamber 1, may be termed thedistillation chamber and 2, the preliminary melting and purificationchamber. The for an opening at one end throughwhich solid material maybe introduced, and except for a drainage conduit 3, which leads from theinclined bottom of chamberl. It will be no ticed that the chamber 2,extends to a lower level than the chamber 1 and has an inclined bottomdirected toward the outlet 3. About midway in one vertical side ofchamber 2 is a passage 4 leading to the inclined bottom of the chamberland serving to connect these two furnace chambers.

constituting but outlet ipe 9 extends from the u er art of the ch mber 1through Pp p any suitable means for densing zinc. The ch against theadmission of air, any suitable means being provided in the passage 9 forthis purpose, it is effectively sealed against admission of air from thechamber 2 by the metal in the connecting passage 4.

It will be understood that the present furnace may be heated in anysuitable manner, although preferably this will be done electrically, thecurrent being supplied to resistance elements placed in the roof of thefurnace, and here shown in the form of granular carbon 6. Thisresistance material is positioned in the form of an arch over thetop ofthe furnace and at either end contacts carbon blocks or electrodes 7which extend exteriorly of the furnace where they may be connected toany suitable source of current. The granular carbon is supported upon alining 8 of fireclay, or a similar nonconducting material, and the heatfrom this carbon is thus diffused slowly and uniformly over the roof ofthe furnace. In this way a very even heat effect can be obtained on thematerial in the furnace, and it will be understood that any suitablemeans for regulating the current may be supplied by this means,preferably taking the form of an external rheostat, although if desiredthe electrodes 7 can be made adjustable and can be moved toward orawayfrom each other to force the granular carbon into varying degrees ofcontact, to secure in this way a variation of the resistance of thismaterial, and consequently a variable temperature in the furnace.

The preliminary heating chamber or furnace may be heated in any one of anumber of ways, but will preferably be heated by means of a granularcarbon electrode 11 extending across the roof of the furnace andconnected supply. This furnace may through an opening 12 in the 'may beclosed by means of a cover 13 during the operation of the furnace, andit will be understood that this charging may be accomplished withoutinterrupting the continuous operation of out affecting the action in thelong as no great amount charged at any one time.

collecting the conamber 1 is closed be charged furnace, so of new metalis the furnace wall to to a suitable source of current Patented Aug. 14,1917.

roof, which I the furnace and with- In order to start up the furnace,crude metal is supplied to the chamber 2, and is there heated until thelevel of metal in this chamber is raised sufficiently to fill thechamber 1 to about the point indicated in Fig. 1. The heat is thenapplied in full force and the metal in the chamber 1 is continuouslyboiled or distilled, the distilled zinc then passing into outlet pipe 9when it can be condensed and collected in suitable receptacles. As fastas the'metal is Withdrawn from chamber 1, additional metal will besupplied to chamber 2 to maintain a level in these two chambers at thedesired height.

The crude metal, which is supplied to chamber 2, contains more or lessiron and lead. As both the lead andiron are heavier than the zinc, theysink to the bottom of the chamber 2, and until a considerable quantityof metal has been melted, the level of the zinc and iron in thischamber, except a small percentage, will not rise to the level ofpassage 4 leading to chamber 1, but when the lead and iron have risen tothe level of passage 1, larger quantities of these metals will enterchamber 1, and as the action continues the zinc will be contaminatedwith. lead and iron.

\Vhenever this contamination reaches the point where theresultingrefined Zinc' is appreciably affected, it is necessary to cool thefurnaces down some- What, and then draw off the lead and iron in thebottom of chamber 2, in this way lowering the level in chamber 1 andcausing the lead and the iron that may be in the zinc in that chamber toflow back into chamber 2, where they will not contaminate the zinc whichhas been purified and has been removed. To secure this action, thetemperature is dropped to about 450 degrees or only a few degrees abovethe melting point of zinc.

The advantages of my improved furnace are its ability to automaticallyretard the passage of lead and iron into the distilling chamber, and theconvenience of drainage of this cliamber in case any appreciable amountof these metals does find its way in.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the processherein disclosed, provided the step or steps stated by any one of thefollowing claims or the equivalent of such stated step or steps beemployed.

I therefore particularly point out and distinctly claim as my invention:

1. In a two-stage method of purifying zinc of heavier metals associatedtherewith,

the steps which consist in melting the'impure zinc in a chamber to allowthe heavier metals to settle, drawing 01f the relatively pure zinc abovethe level of the heavier metal, distilling such drawn ofl metal andallowing the heavier part thereof to drain back into such meltingchamber.

;2. In a two-stage method of purifying zinc of heavier metals associatedtherewith,

' the steps which consist in heating impure zinc in a chamber to atemperature but slightly above the melting point of zinc to allow theheavier metals to settle, drawin off the relatively pure zinc above theleve of the heavier metal, distilling such drawn off drawn metal andallowing the heavier part thereof to drain back into such meltingchamber.

3. In a distillation furnace, the combination of a melting chamberadapted to receive zinc contaminated with heavier metals,

a distillation chamber adjacent thereto and for drawing off the heaviermetals collecting at the bottom of said melting chamber. 5. In adistillation furnace, the combination of a melting chamber adapted toreceive zinc contaminated with heavier metals, a distillation chamberadjacent thereto and connected to drain into the former at a pointspaced from the bottom of the same, means for heating said chambers,means for drawing off the heavier metals collecting at the bottom ofsaid melting chamber, and means for collecting the zinc distilled awayfrom said distilling chamber.

Signed byme, this 2nd day of May, 1916.

RICHARD ZIESING.

Attested by:

E. W. Form, C. H. KLAUsrERMEYnn.

